data-forest 0.1.0.3 → 0.1.0.4

raw patch · 2 files changed

+72/−15 lines, 2 filesPVP: minor bump suggested

API additions: PVP suggests at least a minor version bump

API changes (from Hackage documentation)

Files

• data-forest.cabal +1/−1
• src/Data/Forest.hs +71/−14

@@ -3,7 +3,7 @@ -- see: https://github.com/sol/hpack  name:           data-forest-version:        0.1.0.3+version:        0.1.0.4 synopsis:       A simple multi-way tree data structure.  description:    In some contexts, forests (collections of zero or more trees) are more important than trees. The /data-forest/ library provides a @Tree@ type much like the one from the popular /containers/ library, but it also provides a @Forest@ type with its own @Functor@ and @Foldable@ instances.

@@ -5,7 +5,8 @@  -} -{-# LANGUAGE DeriveFoldable, DeriveFunctor, GeneralizedNewtypeDeriving #-}+{-# LANGUAGE DeriveFoldable, DeriveFunctor, DeriveTraversable,+             GeneralizedNewtypeDeriving #-}  module Data.Forest     (@@ -28,6 +29,10 @@     , subforest     , subtrees +    -- * Folds+    , foldForest+    , foldTree+     -- * Forest functor     -- $functor @@ -35,9 +40,11 @@  import Data.Eq (Eq) import Data.Foldable (Foldable)-import Data.Functor (Functor, fmap)+import Data.Function (($))+import Data.Functor (Functor, (<$>), fmap) import Data.Monoid (Monoid, mempty) import Data.Semigroup (Semigroup)+import Data.Traversable (Traversable) import Prelude (Show)  --------------------------------------------------------------------------------@@ -49,7 +56,7 @@ newtype Forest a = Forest     { trees :: [Tree a] -- ^ The trees that constitute the forest.     }-    deriving (Eq, Show, Foldable, Functor, Semigroup, Monoid)+    deriving (Eq, Show, Functor, Foldable, Traversable, Semigroup, Monoid)  -- | A tree is defined completely by its 'root' and its 'subforest'. --@@ -60,7 +67,7 @@     , subforest :: Forest a -- ^ The forest containing all descendants                             --   of the tree's 'root'.     }-    deriving (Eq, Show, Foldable, Functor)+    deriving (Eq, Show, Functor, Foldable, Traversable)  -------------------------------------------------------------------------------- @@ -93,6 +100,55 @@ subtrees :: Tree a -> [Tree a] subtrees t = trees (subforest t) +{- | Catamorphism on forests.++>>>+:{+example :: Forest Char+example = forest+    [ tree 'a' $ leaves "bc"+    , tree 'd' $ forest+        [ leaf 'e'+        , tree 'f' $ leaves "g"+        ]+   ]+:}++>>> foldForest (intercalate ", " . fmap (\(a, b) -> [a] <> " [" <> b <> "]")) example+"a [b [], c []], d [e [], f [g []]]"++-}+foldForest :: ([(a, b)] -> b) -> Forest a -> b+foldForest f =+    go+  where+    go (Forest ts) = f $ (\t -> (root t, go (subforest t))) <$> ts++{- | Catamorphism on trees.++>>>+:{+example :: Tree Char+example = tree 'a' $ forest+    [ tree 'b' $ leaves "cd"+    , tree 'e' $ forest+        [ leaf 'f'+        , tree 'g' $ leaves "h"+        ]+   ]+:}++>>> foldTree (\a bs -> [a] <> " [" <> intercalate ", " bs <> "]") example+"a [b [c [], d []], e [f [], g [h []]]]"++-}+foldTree :: (a -> [b] -> b) -> Tree a -> b+foldTree f =+    go+  where+    go t = f (root t) (go <$> subtrees t)++ --------------------------------------------------------------------------------  {- $setup@@ -100,6 +156,7 @@ >>> import Prelude >>> import Data.Char >>> import Data.Foldable+>>> import Data.Function >>> import Data.List >>> import Data.Semigroup @@ -138,20 +195,20 @@  >>> :{-printCharForest = putStrLn . showForest+showCharForest f =+    intercalate ", " (showCharTree <$> trees f)   where-    showForest f = intercalate ", " (fmap showTree (trees f))-    showTree t = case trees (subforest t) of-        []   -> [root t]-        [t'] -> [root t] <> ": " <> showTree t'-        ts   -> [root t] <> ": (" <> showForest (subforest t) <> ")"+    showCharTree t = case trees (subforest t) of+      []   -> [root t]+      [t'] -> [root t] <> ": " <> showCharTree t'+      ts   -> [root t] <> ": (" <> showCharForest (subforest t) <> ")" :} ->>> printCharForest example-a: (b, c), d: (e, f: g)+>>> showCharForest example+"a: (b, c), d: (e, f: g)" ->>> printCharForest (fmap toUpper example)-A: (B, C), D: (E, F: G)+>>> showCharForest (fmap toUpper example)+"A: (B, C), D: (E, F: G)"  Likewise, 'Forest''s 'Foldable' instance folds over the elements of the forest.